Stock clamp



July 8, 1952 Filed Jan. 18, 1947 J. G- MOOHL ET AL STOCK CLAMP 2SHEETS-SHEET l INVENTOR-S JOHA N G UJTAF MOOHI- 4m;

BY Vzcroz 7'. TANJK/ July 8, 1952 J. G. MOOHL ET'AL STOCK CLAMP 2SHEETS-SHEET 2 Filed Jan. 18, 194? INVENTORS JOHA G TAF Moo/4L ANDVICTOIEL T-TAN5KI ATTO/ZJVEVS i atented 8, 1 952 STOCK CLAMP JohanGustaf Moohl, Cleveland Heights, and Victor T. Tanski, Cleveland. Ohio,assignors to The Motch & Merryweather Machinery Company, Cleveland,Ohio, a corporation of Ohio Application January 18, 1947,, Serial No.722,772

7 6 Claims. I I

This invention relates as indicated to an improved stock clamp forsawing machines and the like and more particularly to clamping mechanismadapted to be quickly and automatically moved into clamping position andthen firmly lockedagainst displacement during the performance of anoperation upon theworkpiecev Column clamps of the nature described andillustrated in Moohl Patent No. 2,327,920 are adapted to be quicklyadjusted to different sizes of stock and may then be rapidly clamped andunclamped through action of a fluid pressure cylinder. is additionallyadvantageous in that it lends itself to adaptation in the systemof'controls whereby the sawing machine may be automatically operated. Ithas been found advantageous to rotate the rotary saw blade of themachine in such direction that it will cut upwardly into the work. Whilethis helps to maintain the saw carriage firmly seated in the ways, itobviously causes considerable pressure to be exerted against thereciprocable upper jaw of the clamp.v Since such jaw is held in clampingengagement with the work through the exercise of fluid pressure, therewill be a tendency toward chattering as the saw cuts therethrough.

It is, therefore, a primary object of this invention to provide clampingmeans adapted to be reciprocated rapidly into clamping engagement byaction of fluid pressure means, but which will then be mechanicallylocked to prevent such chatter.

It is a further object of this invention to provide such locking meanswhich will automatically lock the reciprocable clamping member themoment it enters into clamping engagement with the stock.

Still another object of this invention is to provide means forautomatically unlocking such clamping member prior to reciprocationthereof out of clamping position. 4

Other objects of this invention will appear as the description proceeds.

To the accomplishment of the foregoing and related ends, said inventionthen comprises the features hereinafter fully described and particularlypointed out in the claims, the following description and'the annexeddrawings setting forth in detail certain illustrative embodiments of theinvention, these being indicative, however, of but a few of the variousways in which the principle of the invention may be employed.

'In-said annexed drawings; j

Fig. 1 is avertical sectional view of a column Such fluid pressureactuating means clamp for a metal sawing machine constructed inaccordance with our invention;

Fig. 2 is a horizontal sectional view taken along the line 2-2 on Fig.'1; and

Fig. 3- is a diagrammatic layout of a fluid pressure system whereby suchmechanism is adapted to be automatically operated.

Referring'now more particularly to said drawing, a saw carriage l ismounted on ways 2 carried by base frame 3 of an automatic sawingmachine. The saw 4 indicated in dash lines on Fig. 1 is adapted to bedriven in a counter-clockwise direction as viewed insuch figure. Suchsaw carriage is reciprocable toward-and away from a column clampcomprising vertically reciprocable upper jaw member *5 and a lower jawcomprising two relatively laterally'adjustable members 6 and 7. Both theupper andlower jaws are vertically divided into two clamping portionsadapted to receive the saw'therebetween when the saw carriage isadvanced to make "a cut. Lower jaw member 6 is fixed to the base 3 ofthe machine and member 1 is adapted to be reciprocated into desiredadjusted position relative thereto by means of hand wheel Bthrough whichthreaded shaft 9 maybe rotated in boss [0 on said member.

Upper jaw 5 is adapted to be vertically reciprocated along a slide-way Hin the front'of housing l2. Member '5 is supported by and is adapted tobe vertically positioned by a screw shaft l3 provided with a hand wheelM, such screw shaft threadably engaging in a quill [5 which is rotatablymounted but longitudinally fixed in a sleeve- IB integral with jaw 5. Itwill thus be seen'that by rotation of hand wheels 8 and M, lower jawmember I may be laterally positioned and upper jaw 5 verticallypositioned to accommodate a variety of stock shapes such as I-beam l'l,square bar it and round bar l9. Lower jaw members 6 and l are providedwith corresponding steps such as 20 in their opposed faces to receivevarious sizes of stock and the edges of one pairof steps are beveled toaccommodate the round bar stock IS. The use of removable inserts toaccommodate various types of stock is thereby avoided The lower end ofshaft I3 is journaled in a boss 2| within housing l2 and a collar 22 issecured to such shaft as bymeans of a set screw adjacent such lower end.A shifter crank '23 carrying a yoke 24 engaged in the peripheral grooveof collar 22 is mounted for oscillation about horizontal shaft 25. Theother end of such crank is connected through link '26 with. an'extensionof piston 21 of fluid pressure cylinder 28. An upstanding arm 29 isformed intee grally with crank 23 and carries a roller 30 at the endthereof. Above such arm and supported by the same bracket 31 whichsupports cylinder 28 is a second smaller cylinder 32. The downwardlyprojecting extension 33 of the piston of such latter cylinder carries awedge 34 adapted to engage roller 30 with its inclined face and to bearagainst a guide-way 35 in a bracket 31 with its opposite face. It willthus be seen that when such wedge is in engagement with roller 30, asshownin Fig. 1, crank 23 is mechanically locked against clockwiserotation about shaft 25. As a result, when stock is fed through theclamp of this invention between lower jaw members 6 and 'i and upper jaw5, such upper jaw may be brought down into clamping engagement with theworkpiece through action of fluid pressure in cylinder 28, rocking crank23 in a counterv clockwise direction. As such crank thus rocks,

wedge 34 descends in continual engagement with bracket 3! and rollerStunder the influence of fluid pressure in cylinder 32. Thus fluidpressure means is employed to reciprocate the upper jaw into and out ofclamping engagement with the work and also to supply the necessarygripping pressure to such jaw, but such jaw will be mechanically lockedin tight clamping engagement with the work so as to be fixed against anyyielding or chattering which might otherwise occur as the saw cutsupwardly through the work.

Referring now more particularly to Fig. 3 of the drawing, the fluidpressure system for operating our new, clampis there diagrammaticallyillustrated in association with the sawing machine operating means.Hydraulicfluid, such as oil, is pumped from sump 35 by pump 3? driven bymotor 38into pressure line 39 and thence through pressure sequence valve40 to a-way valve 4!. To start operation after setting up the machine,the operator shifts control handle 42 to connect line 43 with suchpressure line through valve 44, hand valve 45 having already beenopened. Fluid pressure in line i3 thereupon operates piston-cylinderassembly it to clamp the stock is between the jaws 4? of the stockfeeding mechanism. The stock will then be fed the desired distance pastthe saw blade either manually or, in the case of completely automaticoperation, by. additional fiuid pressure means (not shown).

The operator next shifts control 42 to connect line 48 to pressurethrough valve 44, thereby admitting fluid pressure simultaneously intocylinders 28 and Hand causing clamp jaw 5 to be reciprocated intoclamping engagement with the stock is and locked in such position. Thissame shifting of control 42 reciprocates rod 49 and attached arm 50 toshift valve if, admitting fluid pressure to line 51. Valve it, however,will not be over-balanced to admit fluid pressure to valve 41 until thepistons in cylinders 28 and 32 have ceased to travel and pressure isbuilt up in line During the advance of the saw carriage the rate of suchadvance was regulated by escape of 4 fluid from the other side of piston52 through flow control valve 58. Now when pressure is applied to line51 and line 5| is connected to relief the saw carriage will be rapidlyreturned by passage of fluid through check valve 59.

The return of rod 49 also shifts control 42 to reverse valve 44,connecting line 43 to pressure. This again causes feed gripper 51, whichin the meantime has been returned by the operator, to seize the stock.Fluid pressure in line 60 first returns piston 33, withdrawing wedge 34,and when such piston has retreated sufficiently to uncover port 6| fluidpressure is admitted to line 62 to reciprocate piston 21 in cylinder 28,thereby elevating clamp jaw 5. It will thus be seen that during theclamping operation both pistons are reciprocated simultaneously,advancing the wedge as the jaw is lowered, but when the clamp is to bereleased the pistons are automatically reciprocated in sequence, thewedge being first withdrawn.

The by-pass and check valve 63 is a safety feature whichpreventsadvancing of the saw carriage should the column clamp fail toseize the work. Thus, should jaw 5 not be positioned properly byhandwheel Hi the movement of piston 21 might be insufficient to bring.such jaw into tight engagement with the stock. Reciprocation of suchpiston beyond such by-pass will permit the fluid to escape to relief andsufficient pressure will not be built up in line 48 to overbalance valvetil to admit fiuid pressure to valve 4|. As soon as the operatorproperly adjusts wheel It so that jaw 5 can be moved into firm clampingengagement with the work the operation will resume.

While hydraulic fluid such as oil will ordinarily be employed it will beseen that since jaw 5 is mechanically locked in clamping position airpressure may be utilized to operate the same, if desired. The dividedjaws of the clamp hold the end portion of the stock being cut off andprevent rotation and burring of such section as the cutnears completion.

Other modes of applying the principle of the invention may be employed,change being made as regards the details described, provided thefeatures stated in any of the following claims or the equivalent of suchbe employed.

We therefore particularly point out and distinctly claim as ourinvention:

1. In combination with a metal sawing machine operative to cut upwardlyinto a workpiece,

a work holding clamp including a vertically reciprocable upper clampmember, pivotally mounted lever means connected with and operative toreciprocate said clamp member in response to rocking movement of saidlever, fluid pressure means connected with and operative to rock saidlever, wedge means operative to engage said lever and prevent rockingmovement thereof in a direction to retract said upper clamp member,there,- by mechanically to lock said upper clamp member in clampingposition, and separate fluid pressure means connected with and operativeto advance said wedge means as said upper clamp member is advanced intoclamping position and to withdraw said wedge means prior to actuation ofsaid first-named fluid pressure means to retract said clamp member fromclamping position.

2. In a work-holding clamp,-a first jaw member, a reciprocable jawmember opposed thereto, jaw-operating means including fluid-pressuremeans and a mechanical element adapted to be reciprocated thereby,operative'to shift said second jaw memberinto and out of clampingposition relative to said first jaw member, wedge means adapted toengage said element to prevent movement thereof in a direction tounclamp said second jaw member, and separate fluid-pressure meansoperative to advance said wedge means closely to follow said element asthe latter is reciprocated to shift said second jaw member towardclamping position and to withdraw said wedge means independently ofactuation of said element whereby the latter may at once thereafteroperate to unclamp the work.

3. In a work-holding clamp, a lower jaw member, a verticallyreciprocable upper jaw member opposed thereto, a vertically disposedaxially reciprocable and rotatable shaft threadedly engaging said upperjaw member for adjustably positioning the latter therealong, a pivotallymounted lever connected with and adapted thus axially to reciprocatesaid shaft, fluid-pressure means connected with and operative to rocksaid lever to reciprocate said shaft and said upper jaw member into andout of work holding position, an arm on said lever, a fixed straightguideway, wedge means interposed between said lever and guideway adaptedto engage said lever to prevent movement thereof in a direction tounclamp said upper jaw member, and separate fluid-pressure meansoperative to withdraw said wedge means to permit'said first-namedfluid-pressure means at once to rock said lever to unclamp the work.

4. In a work-holding clamp, a lower jaw memher, a verticallyreciprocable upper jaw member opposed thereto, a pivotally mounted leveradapted thus to reciprocate said upper jaw member, fluid-pressure meansconnected with an operative to rock said lever to reciprocate said upperjaw member into and out of work-holding position, a fixed straightguideway, reciprocable wedge means interposed between said lever andguideway adapted to engage said lever to prevent movement thereof in adirection to unclamp said upper jaw member, and separate fluid-pressuremeans operative to advance said wedge means closely to follow said leveras the latter is rocked to shift said upper jaw member toward clampingposition and to withdraw said wedge means independently of actuation ofsaid lever whereby the latter may at once thereafter operate to unclampthe work.

5. In a work-holding clamp, a lower jaw member, a verticallyreciprocable upper jaw member opposed thereto, a pivotally mounted leveradapted thus to reciprocate said upper jaw member, fluid-pressure meansconnected with and operative to rock said lever to reciprocate saidupper jaw member into and out of work holding position, a fixed straightguideway, reciprocable wedge means interposed between said lever andguideway adapted to engage said lever to prevent movement thereof in adirection to unclamp said upper jaw member, separate fluid-pressuremeans operative thus to reciprocate said wedge means, and control meansfor said two fluid-pressure means operative simultaneously to actuatethe same to rock said lever to move said upper jaw member towardclamping position and to advance said wedge means closely to follow saidlever as the latter is thus rocked, said control means being operativesequentially to actuate said two fluidpressure means first to withdrawsaid wedge means and thereafter to rock said lever to shift said upperjaw member away from said lower jaw member to unclamp the work.

6. In a work-holding clamp, a lower jaw member, a verticallyreciprocable upper jaw member opposed thereto, a vertically disposedaxially reciprocable and rotatable shaft threadedly engaging said upperjaw member for adjustably positioning the latter therealong, a pivotallymounted lever connected with the adapted thus axially to reciprocatesaid shaft, a fluid pressure operated piston-cylinder assembly connectedwith and operative to rock said lever thereby to reciprocate said shaftand said jaw member into and out of work clamping position, an arm onsaid lever having a roller mounted on the free end thereof on an axisgenerally parallel to the pivotal mounting of said lever, a fixedstraight guideway, reciprocable wedge means interposed between saidroller and guideway adapted to engage said roller to prevent rockingmovement of said lever in one direction to unclamp said upper jawmember, a second fluid-pressure operated piston-cylinder assemblyoperative thus to reciprocate said wedgemeans, and control means forsaid two pistoncylinder assemblies operative simultaneously to actuatethe same to rock said lever to move said upper jaw member towardclamping position, and to advance said wedge means closely to followsaid roller on said lever arm as said lever is thus rocked, said controlmeans being operative sequentiall to actuate said fluid pressureassemblies first to withdraw said wedge means and thereafter to rocksaid lever to shift said upper jaw member away from said lower jawmember to unclamp the work.

JOHAN GUSTAF MOOHL. VICTOR 'I'. TANSKI.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,498,638 Periolat June 24, 19241,669,264 Reis May 8, 1928 2,168,772 Huffman Aug. 8, 1939 2,289,140Mohan July 7, 1942 2,327,920 Moohl Aug. 24, 1943 2,397,974 Morrow et alApr. 9, 1946 FOREIGN PATENTS Number Country Date 406,824 Great BritainMIar. 8, 1934 463,312 Great Britain Mar. 19, 1937 512,082 Germany Nov.6, 1936

